Carriage decelerating mechanism for telegraph page printers



Dec. 29, 1964 5, sum 3,163,261

CARRIAGE DECELERATING MECHANISM FOR TELEGRAPH PAGE PRINTERS Filed Oct. 15, 1962 FIG. 3

INVENTOR GORDON SIM ATTORNEY United States Patent Ofitice 3,163,261 CAGE DEQELERATING MECHANISM FOR TELEGRAPH PAGE PTERS Gordon Sim, Northbrooir, 11L, assignor to Teletype Corporation, Skokie, 111., a corporation of Delaware Filed Get. 15, 1962, Ser. No. 230,549 Claims. (Cl. 188-94) This invention relates to a carriage deceleration mechanism for telegraph page printers and more particularly to a self-aligning deceleration mechanism for dampening the shock of the return travel of the printing carriage upon the execution of a carriage return function.

It is an object of the present invention to provide a simplified deceleration mechanism for the carriage of a telegraph page printer.

Another object of the invention is to provide a deceleration piston and cylinder arrangement which is selfaligning.

In accordance with the present invention a carriage decelerating mechanism is provided which is particularly useful in a page printer of the type disclosed in the copending application of W. J. Zenner, Serial No. 159,330, filed December 14, 1961. The disclosure of this copending application is incorporated herein as though reproduced completely in this application to facilitate an understanding of the construction and operation of the mechanism of the present invention.

In said'copending application there is shown and described a printing telegraph page printer of the 'type wherein a non-reciprocal but rotary platen is used and wherein printing is effected by a type wheel which is carried by a carriage to traverse the length of the platen to effect spacing of the characters printed in a line on paper carried by the platen. The type wheel and its cooperating positioning mechanism are carried on a casting to which there is attached a piston which, according to the present invention, may move radially of its axis to a relatively large extent to achieve alignment with a stationary dashpot cylinder. The dashpot cylinder is mounted on the framework of the printer in a fixed position and the piston is attached to the casting so that it cannot move axially with respect to the casing but may move radially with respect to the casting to align itself with the dashpot cylinder. The piston is frictionally engaged with the casting so that it will tend to remain in any radial position to which it is moved with respect to the casting.

A more complete understanding of the invention may be had by reference to the accompanying drawings wherein:

FIG. 1 is a fragmentary elevational view partly in section and partly in front elevation of a printing telegraph page printer including the deceleration mechanism of the present invention;

FIG. 2 is a sectional view taken through the piston and dashpot cylinder and througha portion of the casting to which the piston is attached;

'FIG. 3 is an end view ofthe dashpot cylinder taken substantially along the line 3-3 of FIG. 1 in the direction of the arrows, and

rows showing a port-ion of the casing in section and the end of the piston in elevation.

Referring now to the drawings wherein like reference numerals designate the same parts throughout the several views it will be noted that the reference numerals used in the copending application of W. J. Zenner identified hereinbefore have been used in the drawingto facilitate an understanding of the cooperation of the decelerating mechanism of the present invention with the apparatus disclosed in said copending application.

In the copending application a casting 145 supports the type wheel mechanism and is moved step-by-step across the printer to associate a type wheel 186 with succeeding areas of a web of paper on a platen 271. The

casting 145 is supported on a guide rod 146 and is stepped ing 145 and the mechanism supported thereon, including a print hammer 293, move across the platen 271. A

driving pawl 467 which is actuated each time the printing telegraph apparatus receives either a character printing or a spacing code combination, serves to drive the ratchet 466 and the ratchet 466 will be retained in its advanced position by a detent pawl 468. These mechanisms serve to step the casting 145 to the right as viewed in FIG. 1 against the tension of a coilspring 488. This coil spring 488 has the end of its upper course hooked over a stud 489 mounted on the casting 145 and the coil spring 488 has the right end of its lower course attached to a suitable portion of the framework. Intermediate the two courses of the coil spring 48 8, the spring passes around a guide roller 491 which is freely rotatable about,

a stud shaft 492 that. also supports a space function restoring lever 493.

Upon receipt in the apparatus of a code signal calling for a carriage return operation a pawl release lever 480 will be actuated, as described in detail in the aforementioned copending application of W. J. Zenner, todisengage the driving pawl 467 and the 'detent pawl 468 from the teeth of the ratchet 466. The pawl release lever 480 will be latched in its actuated position to permit the coil spring488 to return the casting '145 to its extreme left-hand position, at which point thecasting will strike the space function restoring lever 493' to re store the driving pawl 467 and detent pawl 468 to operating relationship with the ratchet 466. 7

From the foregoing it isbelieved to be apparent that in the normal operation of the printing telegraph appa- FIG. 4 is a vertical sectional view taken substantially along the line 4-4 of FIG. 1 in the direction of the arratus the casting will be moved step-by-step to the right (FIG. 1) being guided by guide rollers 152 and which are mounted on extensions 153 and156 and which ride on the guide rod 146. This movement of the casting 145 to the right will stretch the coil springs 488 to store energy in it for restoring casting 145 and the mechanism on it to the left-hand position when a carriage return signal is received in the apparatus.

The platen 271 is supported for rotation in a platen supporting plate 432 and a cooperating platen supportmg plate (not shown). I The plate 432 is supported by a bracket 434 that is in turn suitably-mounted on a side 1 plate 149 of the apparatus. The side plate 149 also sup ports a dashpot cylinder 10 for cooperation with a piston or plunger 11 which is mounted on the casting 145. The' dashpot cylinder 10 has a cylindrical wall portion 12 that is tapered at its right end as shown at 13(FIG. 2) 1 and has a base portion 14 in which there is formed an exhaust port 15. The effective size of the 'exhaustport 15 maybe controlled by a lever 16 which is pivoted on the shank of aretaining screw 17 threaded into the base portion 14. After the lever '16 has been moved to adjust.

the effective size of the port 15, the lever 16 may be locked in place 'by tightening the retaining screw .17.

.The dashpot cylinder 10 has cooperating'with it the plunger or piston-11 which comprises a cylindrical cupshaped member 18 having a ridge 19 formed on its base as shown. in FIGS. 2 and'4. .A soft rubber disc 20 is forced into the cupkshaped member 18' and 'is-p'rovided with a recess 21 into which a projecting portion of a" 3,163,261 Patented Dec, 29, 1964 3 stud 22 extends. This stud 22 is formed integrally with the casting 145. The base of the cup-shaped member 18 has a relatively large hole 23 formed in it through which the stud 22 extends. The casting 145 has three arms 24, 25 and 26 formed on it, on which the ridge 19 rides. The cup-shaped member 18 is held with its ridge 19 in engagement with the arms 24, 25 and 26 by a coiled spring 27 which surrounds the stud 22 and is interposed between a cup-shaped washer 28. and a flat washer 29. The flat washer 29 surrounds and slidingly engages the stud 22 and the cup-shaped washer 28 is slidable on the stud 22 but is retained in the position shown by a clip 36 which is a Washer with a slot cut in it for engaging the peripheral surface of an annular groove 31 formed adjacent the left-hand of the stud 22.

With this arrangement, the cup-shaped member 18, which has a peripherally extending taper 32 formed on it, will be resiliently held against the arms 24, 25 and 26 by the'pressure of the spring 27 and will remain in any position to which it is moved within the limits of the size of the hole 23 and the diameter-of the projecting portion or stud 22. The cup-shaped member 18 is formed. to an outside diameter a few thousandths of an inch less than theinside diameter of the cylindrical wall portion 12 of the dashpot cylinder 10. When a carriage return operation takes place the spring 488 will move the casting 145 to the left (FIG. 1) and into the position shown in FIG. 2.

With the mechanism just described the shocks usually incurred by a carriage mechanism, such as that which includes the casting 145 and the parts carried by it, will be reduced to an acceptable minimum. For example, if the printer apparatus is handled roughly in being moved from one position to another with the casting 145 in its extreme right-hand position whereby the plunger 11 is moved from its centered position as shown in FIG. 2to a. position where the upper surface of the hole 23 engages the upper surface of the stud 22, the plunger 11 will be out of alignment with the dashpot cylinder 10. 'When such a condition exists the spring 488 will have the maximum amount of kinetic energy stored in it and when a carriage return operation is initiated the spring 438 will snap the carriage and casting to the left (FIGS. 1 and 2) with great force. The casting 145 in returning to the left will move the plunger 11 with it and in entering the dashpot cylinder the taper 32 formed on the cup with the dashpot cylinder 10. This will move the plunger to approximately the position shown in FIG. 2 where the plunger will be retained by the pressure of the spring 27. On succeeding carriage return operations, of course, the automatic centering of the plunger 11 with the dashpot cylinder 10 will not require a great amount of movement of the plunger 11 with respect to the casting 145. However, if vibrations of the printer in its normal oper-' ation cause the plunger 11 to shift, in spite of the pressure of the spring 27 forcing the ridge 19 against the surfaces of the arms 24, 25 and .26, the plunger llwill center itself with respect to the dashpot cylinder 10.

When the plunger 11 centers itself with respect to the dashpot cylinder 10, the clearance between the wall 220 and outer-surface of the cup-shaped member 11 will restrict the'flow of air out of the dashpot 10 and in cooperation with the port 15, whose opening has been: adjusted by manipulating the lever 16, will decelerate the movement of the casting 145 as is usual in such devices. If the type carriage. including the casting 145 is moved only a short distanceto the. right (FIG. 1) to withdraw the plunger 11 only a short distance out of the dashpot cylinder 10 the decelerating effect of the restricted port and clearance between the wall 12and cup-shaped member 18 will, of course, be decreased but in like manner the pressure spring 488 will also be decreased. When 4 a short movement to the right has been imparted to the casting and then a carriage return signal is received in the apparatus, the soft rubber disc 20 will serve to cushion the shock of the carriage return operation.

Although only one embodiment of the invention is shown in the drawings and described in the foregoing specification, it will be understood that invention is not limited to the specific embodiment described but is capable of modification and rearrangement and substitution of parts and elements without departing from the spirit of the invention.

What is claimed is:

l. A decelerating mechanism for dampening the return shock between a pair of relatively movable elements that are moved apart under power and returned under spring pressure, comprising a dashpot plunger member on one of said elements and a dashpot cylinder member on the other of said elements, cooperative tapered surfaces on said dashpot members for camming said members into 'axial alignment with respect to each other, means for fixing one of said members on one of said elements, and friction means on the other of said elements tending to hold the other of said members in any adjusted position on the other element to which said other member is moved by the elements being returned under spring pressure to move the dashpot plunger member into the dashpot cylinder member whereby the'cooperating tapered surfaces on said members will cam the other of said members into substantially axial alignment with said one member.

2; A decelerating mechanism for dampening the return shock between a pair of relatively movable elements that V ments, cooperating tapered surfaces on said dashpot cylin- V ders and said dashpot plunger for camming the plunger into axial alignment with the dashpot cylinder, means for fixing the dashpot cylinder on one of said elements, and friction means on the other element frictionally clamping the dashpot plunger on the other element and tending to hold the dashpot plunger in an adjusted positionwith re-' spect to the other element whereby, when the dashpot plunger is not exactly axially aligned with the dashpot cylinder, the cooperating tapered surfaces on the dashpot cylinder and dashpot plunger will shift the dashpot plunger with respect to the element on which it is frictionally clamped to substantially axial alignment with-the dashpot cylinder when said elements are returned by said spring pressure.

3. A decelerating mechanism for dampening the return shock between a pair of relatively movable elements that are moved apart under power and returned under spring pressure comprising a dashpot plunger on one of said elements and a dashpot cylinder on the other of said elements, cooperating tapered surfaces on said dashpot cylinder and said dashpot plunger for camming the dashpot plunger into axial alignment with .the dashpot cylinder, means for fixing the dashpot cylinder on one of said elements, and friction means on the other element frictionally clamping the dashpot plunger on the other element and tending to hold the dashpot plunger in an adjusted position with respect to the other element whereby when the dashpot plunger is not axially aligned with the dashpot cylinder, the cooperating tapered surfaces on the dashpot cylinengagement with the arms including a spring encircling the stud, a washer encircling the hole and hearing against the plunger, and means on the stud for holding the spring under compression between the stud and the plunger.

4. A mechanism according to claim 3 in which the dashpot plunger is cup shaped and has a soft rubber member forced into it which encloses the portion of the stud extending through the hole in the dashpot plunger.

5. A decelerating mechanism for dampening the return shock between a pair of relatively movable elements that are moved apart under power and returned under spring pressure, comprising a dashpot plunger on one of said elements and a dashpot cylinder on the other of said elements, cooperating tapered surfaces on said dashpot cylinder and said dashpot plunger for carnming the dashpot plunger into axial alignment with the dashpot cylinder, means for fixing the dashpot cylinder on one of said elements, and friction means on the other element frictionally clamping the dashpot plunger on the other element and tending to hold it in an adjusted position with respect to the other element whereby when the dashpot plungeris not exactly axially aligned with the dashpot cylinder the coeperating tapered surfaces on the dashpot cylinder and d'ashpot plunger will shift the dashpot plunger with respect to the element on which it is frictionally clamped to substantial uial alignment with the dashpot cylinder when said elements are returned by said spring prccess, the friction means comprising the sole means for supporting the dashpot plunger on the element on which it is frictionally clamped and said friction means includes a stud extending from the element, a Washer fixed to the stud adjacent its free end, a washer hearing on the surface of the dashpot plunger and a spring interposed between said Washers to urge the dashpot plunger to frictional engagement with the element on which it is mounted. V 7

References Cited in the tile of this patent UNITED STATES PATENTS Re. 4,776 Cottrell Mar. 5, 1872 1,979,510 Vischer Nov. 6, 1934 FOREIGN PATENTS 263,298 Great Britain Dec. 30, 1926 

1. A DECELERATING MECHANISM FOR DAMPENING THE RETURN SHOCK BETWEEN A PAIR OF RELATIVELY MOVABLE ELEMENTS THAT ARE MOVED APART UNDER POWER AND RETURNED UNDER SPRING PRESSURE, COMPRISING A DASHPOT PLUNGER MEMBER ON ONE OF SAID ELEMENTS AND A DASHPOT CYLINDER MEMBER ON THE OTHER OF SAID ELEMENTS, COOPERATIVE TAPERED SURFACES ON SAID DASHPOT MEMBERS FOR CAMMING SAID MEMBERS INTO AXIAL ALIGNMENT WITH RESPECT TO EACH OTHER, MEANS FOR FIXING ONE OF SAID MEMBERS ON ONE OF SAID ELEMENTS, AND FRICTION 